Boiler water conditioner and blowoff system



,Feb.'1,1944. Q GUNDERSON Em 2,340,468

BOILER WATER CONDITIONER A ND BLOW-OFF SYSTEM Filed'Dec. 4, 1941 3Sheets-Sheet 2 ZNYEZ-LZDZ-TE Ew/url 0. @aA/ofeco/v. OLA/va h4 @fee/cae.

Feb- 1, 1944- L. o. GuNDERsoN Erm. 2,340,468

BOILER WATE CONDITIONER'ND BLOW-OFF SYSTEM 1941 3 Sheets-Sheet 3 FiledDec. 4

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latented Feb. ,1, 1944 BOILER WATER CONDITIONER AND BLOWOFF SYSTEM LewisO. Gunderson, Park Ridge, Ill., and Oland W. Carrick, San Clemente,Calif., asslgnors to Electro-Chemical Engineering Corporation,

Chicago, lll., a corporation of Delaware Application Deeember 4, 1941,serial No. 421,556

12 claims. l (o1. 122-489)4 .This invention relates to the removalofimpurities from boiler water in operating steam boilers and to themaintenance of a clear steam channel un'der the stem outlet of theboiler.-

More specifically, this invention relates to improvements in collectingtroughs or receptacles for collecting light water and foam from the mainboiler courses of operating steam boilers along a path extending fromthe hottest portion of the boiler to the steam outlet.

This application is a continuation in part of our copending applicationSerial No. 254,176, filed February 2, 1939, now Patent No. 2,282,775,issued May l2, 1942. f While the invention will hereinafter be describedin connection with locomotive steam boilers, it should be understoodthat the invention is not limited t`o such use but is useful `in steamboilers in general for controlling foaming of the boilers so that wateror other impurities are not discharged with the steam. l

Locomotive boilers include a Water space,V a steam space, a'l steamoutlet communicating with' the steam space, and a re box inlongitudinally spaced relation from the steam outlet. The hottestportion of the water space is adjacent the fire box and the boiler.`water thus flows forwardly from the fire box end of the water space. Inaccordance with this invention an elongated open topped trough ismounted in the boiler to extend from a point adjacent the fire box .end

' thereof to a point forwardly of the steam dome with an intermediateportion passing directly un` der the steam, dome. This trough is openalong its entire length to the steam space but'hasside and end 'wallsprojecting above the normal Water level so that good boiler water isreceived into the trough.

In locomotive boilers the low level'of the water glass or gauge in theengineers cab must be a minimum of three and one-half inches above thehighest ypoint of the crown? sheet for the fire box. The water glass isusually about eight inches long so that with a full glass of `water, thewater level in the Lboiler will be about eleven and onehalf inches abovethe crown sheet. In accordance with this invention the top of thecollecting trough lis positioned. about two to eight inches above theVtop of the Water glass'or about thirteen to twenty inches above thevcrown sheet.

On the average the steam space above the water I in the boiler with thewater 'glass indicating onehalf full is fifteen to twenty inches high. Afull space through which the steam must pass to the steam outlet. Thissteam spacel of normal height is well suicient to permit the larg'evolume of steam generated inthe boiler to reach the steam dome or outletpipe atf relatively low speeds. However, when foaming develops in theboiler Water the steam expandedor foaming water fre. quently lls thesteam space to a point where the steam has little or no clear passage tothe steam outlet.`

'I'hus the steam path is closed up and the steam necessary for drivingthe locomotiveniust pass through a small space .in sufficient volume tomaintain operation. As a result, the steam approaches hurricane speedsand sweeps the -water and foam into the outlet pipe.

'I'he expansion or foaming of the water in the boiler resulting in adecreasexin height of the steam space depends on several factors Vsuchas the rate of steam generation, the foaming characteristics of the feedwater used in the boiler,

and the like. When the rate of steam generation is high, the greatestswelling or foaming will occur. Frequently when the boiler is workingunder heavy load the entire steam space will be flooded with steamexpanded water or foam and only very' low quality steam can bedeliveredto the outlet pipe.

The present invention, however, maintains a clear steam channelextending from a short distance infront of the steam dome rearwardly'un-v derneath the steam dome to a point near the nre box. Even thoughthe rest of the steam spa'ce is oiledA with foam or steam expandedwatenthe i open topped trough of this invention will maintain the clearsteam channel from the point of' y major steam generation to thedischarge outlet because steam `or light waterv spilling into the opentopped trough will be collapsed and the co`llapsed water will be removedfrom the boile'rautomatically through electrode controls' positionedglass of water'will reduce this spaceA about four inches leaving elevento sixteen inches of open 'at various levels in the boiler.

The elongated trough of 'this invention has a prow-like nose at 'the endthereof adjacent the g re box so as not to interfere with. the .forward-ow of boiler water along the main course of the boiler. The main drypipe of th locomqtivelextends through the other end of the trough andwalls of the trough can have doors provided therein so that access canbereadily had to theA interior of. the steam boiler b'y removal of thesteam dome.

In one embodiment of the blow-:off system according to this invention arearelectrode is l0- sheet.

above the top of the foam collapsing trough preferably at a point abovethe re box or crown sheet. v Whenever foaming water or solid vwateroverflows into the trough and rises high enough to contact this rearelectrode for twenty to thirty seconds, a time-delay switch iaactuate'dtoi close a circuit which causes a light to show in the' engineerscaband at the same time causes a solenoid air valve to operate foropening a blow-oir valve to remove water from the trough. As soon as thefoam or water drops away from contact with this rear electrode thecircuit is broken and,

after a short delay period, the light goes out, the

solenoid air valve closes, and the blow-oil valve closes.

In this same modication a front electrode is located inside of thetrough and ends preferably at a slightly higher level than the rearelectrode. When foamy water contacts this electrode a pair of lightswill show in the engineers cab and the solenoid air valve and blow-oilvalve will open instantaneously to remove water from the trough andthereby clear the channel for free ow of' steam to the outlet pipe.

In another embodiment of the invention double protection against watercarry-over into the outlet pipe is provided. In this embodiment threeelectrodes are used above the collecting trough. A long electrodeextends from the top of the boiler to a point near the bottom of thecollecting trough. A medium electrode ends near the top of the trough,and a short electrode ends above the medium electrode. When foamy orsolid water accumulates in the troughto contact the end of the mediumelectrode an electrical relay is closed lighting a signal light in theengineers cab and opening a solenoid air valve to open a blow-oil valve.This relay is kept closed until the blow-oil valve removes water fromthe trough to a level below the end of the long electrode. When theelectrical circuit is broken by the water dropping away from the longelectrode, the signal light is extinguished and the-blow-oil valve isclosed. The short electrode, when contacted by foamy or solid water,will actuate an electric circuit operating two signal lights in theengineers cab and immediately cause the blow-oft valve to open. Thisshort electrode can be positioned above the trough or` above the crownThe blowing oi of the boiler is thus automati cally accomplished throughelectrodes positioned at different levels in the boiler and thecollapsed foam or light water in the elongated trough is removed. It hasvbeen found that the water collected in this trough'contains a highconcentration of foam producing impurities so that the discharge ofwater from the trough greatly aids the maintenance of reduced solidsconcentration in boiler water. In lother words. the most co'ntaminatedwater is removed from the boiler without sacricing the less contaminatedor good boiler water.

It is, then, an object of this invention 'to provide a long open-toppedtrough extending from I a short distance in front of a locomotive steamdome rearwardly under the steam dome to a point near the iire box.

A further obiect'of this invention is to maintain a clear steam channelalong an open topped trough from a point of major steam generation in aboiler to the steam outlet of the boiler.

A still further object of this invention is to prevent water carry-overin locomotive boilers y examples, illustrate two embodiments of theincated in the boiler to terminate about two inches by collection ofcontaminated water in the boiler at levels of about thirteen to twentyinches above the crown sheet of the boiler.

A further object of the invention is to collect steam expanded or foamywater in an operating steam boiler along a path extending from the crownsheet of the boiler under the steam dome at a level above the normalwater level in the boiler but below the level of the steam outlet.

A still further object of the invention is to automatically dischargecontaminated water from a nonsteam generating channel in the upperportion of a boilerwhenever foam or steam expanded water reaches adangerous level and to continue the discharge of the collected water formaintaining a depressed clear steam channel in the boiler. e

A specific object of the invention is to provide a foam collapsingtrough for steam boilers with a prow-like end facing the normal iiow ofwater in the boiler to prevent splashing and interference with the flow.

- A still further object of the invention is to r provide automaticelectrode discharge control for collapsed foam and light water collectedin the upper portion of the boiler to insure delivery of dry steam fromthe boiler.

Other and further objects of the invention will be apparent to thoseskilled in the art from the following detailed descriptions of theannexed sheets of drawings which. by way of preferred 'ventiom On thedrawings:

Figure 1 is a fragmentary, somewhat diagrammatical side elevationalview, with parts broken away and shown in vertical cross section, of alocomotive boiler equipped with the apparatus of this invention. A

Figure 2 is a fragmentary top plan view of the boiler shown in Figure 1with parts of the boiler shell broken away along the line II-II ofFigure 1 to illustrate the foam-collapsing trough.

Figure 3, is an enlarged fragmentary vertical.

cross-sectional View `with parts in elevation, of the foam-collapsingtrough and electrode assembly of Figure 1.

Figure 4 is an enlarged vertical cross-sectional view, with parts inelevation, and with other parts omitted, taken along the line IV-IV ofFigure 1.

Figure 5 is an enlarged vertical cross-sectional view, taken along theline V-V of Figure l.

Figure 6 is a wiringdiagram `of the electrode system used in theembodiment of the invention shown in Figures 1 to 5.

Figure 7 is an enlarged vertical cross-sectional view, with parts inelevation, similar to Figure 3 but illustrating a .modified electrodearrangement in accordance with this invention.

Figure 8 is a wiring diagram of the electrode system used in theembodiment of the invention shown in Figure '1. A As shown on thedrawings:

In Figures 1 to 5 inclusive the reference numeral II) designatesgenerally a locomotive having the usual boiler shell II defining aboiler course I2. A fire box I3 is provided in the rear end of theboiler and flfe tubes such as Il project forwardly from the fire box I3through the boiler course. The usual engineers cab I5 (Figure 1) ismounted around the rear end of the boiler.

An opening I6 is provided in the top of a boiler shell I l and theopening is covered with the usual steam dome I1. A steam throttle pipeI8 or main outlet pipe to the operating cylinders of the locomotiveextends upwardly at its inlet end into the steam dome I1. Turret pipesI9 or outlet steam pipes to the locomotive and train appur- .wall orlcrown sheet of the re boxvI3 as shown in Figures 1 and 3.

In accordance with this invention an open topped elongated boxvor trough20 is suspended in the upper portion of the boiler on straps 2| securedto the boiler shell II. The box 20 extends forwardly from the hottestportion of the boiler adjacentthe lire box I3, under the steam outletopening I6 of the boiler shell to a point forwardly of the steam outlet.

The box has a bottom, side walls and end walls which cooperate toprovide an elongated channel or nonsteam generating course in the steamspace of the boiler. project into thesteam space S. S. but terminate inspaced relation below the top or the boiler shell so as to place theentire interior of the box along its length in communication with thesteam space. The top of the box is preferably about thirteen to fifteeninches above the Icrown sheet of the tire box, while the bottom of thebox is submerged in the boiler water.

The end of the box 20 adjacent the fire box I3 has a prow-like nose 20awhich, as best shown in Figure 2, is pointed at the longitudinal centerline of the box and, as best shown in Figure 3, slopes backward from theupper edge of the box.

'This nose presents diverging end walls to the forward longitudinal flowof water in the boiler so as to interfere as little as possible withthisv forward flow and to prevent splashing of the boiler Water as ithits the box.

The rear end wall 20h of the box, as best shown in Figure 4, has anopening 22 therethrough for receiving the throttle pipe I8. A collar orstrap such as 23 (Figure 3) secures the" box to the throttle pipe andseals the end wall against leakage around the throtue pipe.

'The side walls 20c of the box or trough have cutaway portions underthesteam outlet I6 so as to permit access to the interiorof the boiler fromthe steam dome. These openings are normally closed by doors 24 which arevhirigedly connected as at 25 tothe box so that they can be moved fromvertical closed position to horizontal open position. .The doorsv areheld in closed positions per side edges thereof and having Wall-engagingThe side and end walls hook-like ends 26a adapted to engage the innerandouter faces of the adjacent wall portions 20c. A blow-off valve 21. ismounted on the boiler shell and is connected through a pipe line 28 withf an outlet 29 in a side Wall 20c of the box 20 at the electrode 35 willbe hereinafter space S. S. of the boiler.

liquid material is drained from the separator 3l to the road bed througha discharge line 33.

The box or'trough 20 has a small vent hole or discharge opening 34(Figure 4) in the other side wall 20c thereof to drain Water from thebottom of the box back to the main boiler. course. 'This drain openingonly accommodates a small return flow of water collected in the troughback to the main boiler course to prevent opening of the blow-oir valve21 when boiler water merely spills into the top of the trough due tomovement of the locomotive boiler as it rocks over an uneven track.

It is not desired to discharge the boiler water I'he actuation of theblow-olf valve 21 is con' trolled by electrodes 35 and 36 mounted inthetop of theboiler shell and projecting into the steam The rearelectrode35 is mounted above the crown sheet of the fire box I3 and terminates ata level above the top of the collecting box 20. The front 4electrode 36is mounted above the rear end of the b'ox and projects into the steamspace S. S. to the same level or a. slightly higher level than theelectrode 35. The electrode 35 is thusA positioned at a very :hot pointin the boiler where maximum steam generation occurs. Whenever steamexpanded water or foam contacts the electrode 35 for a continuous periodofabout twenty to thirty seconds. a circuit is completed to operate atime-delay switch which releases air to the blow-olf valve 21 foropening the valve.y Foam and light water collected in the trough willthen be dischargedcut l of the opening, 29 in the box, through the pipeline 28 and out of the boilerthrough the open blow-off valve 21. Thedischarge will continue las long as the electrode 35 is in contact withwaterin the boiler. When the foam or-water level drops away from theelectrode 35 the valve 21' will remain open for a iixed period tosubstantially empty the trough 20.

When the electrode 36 contacts foamy or solid water the blow-oil valve21 is immediately opened. Thus the rear electrode 35 eects opening ofthe valve after the foam or light water has contacted it for apredetermined period while the front electrode immediately opens thevalve because it receives the foam and light water closer to the steamoutlet and at a point where the foam and light water is more apt to beentrained with the steam. The front electrode 36 is more of an.emergency actuator for thesystem since it will not open until the*bx iscompletely lled and overflowing with the foamy material, whereopened thedischarge.

The time-delay mechanism controlled by the described in connection withFigure 6.

As shown in Figure 2 the box 20 is open along the entire top thereof tothe steam space and foam or light Water developed on top of the mainboiler water can spill into the trough at any point along the lengththereof; Since the trough extends under the steam outlet it will protectthe inlets of the pipes I8 and I9 and will prevent foam from rising intothe steam dome to a. level so a's to enter the pipes. At the saine timethe trough maintains a clear steai'n channel from the hotter portion ofthe boiler adjacent to the nre box forwardly to the steam outletv point.

- The electrodes control the discharge of the imoff is entirelyautomatic.

purities collected in the elongated trough in the manner illustrated inthe electrical diagram of Figure 6. As shown in Figure 6, a generator Gor other source of current has the positive side thereof connected to amainline 40 and has the negative side th'ereof, connected to a main line4I A steam turbo-generator can conveniently be used as a source ofelectric current since the same can be driven by steam from the boiler.Whenever the foam level F. L. in the boiler contacts the rear electrode35 current will flow between the wires 40 and 4I through a relay R1 asshown. The relay R1 closes a relay switch R. S.1 to flow current througha heating element H. `E. for closing a time delay switch T. D. S. byheating a bi-metallic switch element therein. When the time-delay switchis closed current will ilow through a bottom light B. L. in theengineers cab to light the same and will also ilow through the solenoidvalve S. V. to open the valve. Thus the bottom light will be lit and thesolenoid 'valve will be. opened at a predetermined period after the foamlevel contacts the electrode 35. With the solenoid valve open, air underpressure from any suitable source on thelocomotive can flow from pipeline 42 through the valve and into pipe line 43 for opening theair-controlled blow-oil valve 21. A

When the foam level F. L. subsides away from the electrode 35 thecircuit through the relay R1 will be broken and the relay switch R. SJwill open. The heating element H. E. will thus start to cool and thetime-delay switch T. D. Srwlll open as soon as the bi-metallic elementthereof has been cooled suiliciently to cause the switch to open. Thusthe solenoid valve S. V. will continue to be energized for apredetermined period even after the foam level has subsided from theelectrode 35. This delayed action in closing the solenoid valve willpermit the trough 20 to be substantially emptied.

When the foam level contacts the electrode 36 current will dow through arelay R2 which will close normally open relay switches R. Sm and R.$.22. Relay switch R. $.21 will energize the solenoid valve to permitair ilow therethrough and effect an opening of the blow-oil* valve 21.Relay switch R. $.21 will also close a circuit to the bottom light B. L.to light the same. Relay switch R. Ssn will energize the top light T. L.in the engineers cab. Thus, as soon as the electrode 36 contacts thefoarny water, both lights will light and the blow-off will open. As soonas the foam level subsides from the electrode 36 both lights will shutoil and the solenoid valve will close unless the electrode 35 is holdingthe timedelay switch T. D. S. in closed position. If the electrode 35 isholding the switch T. D. S. closed the bottom light only will remain on.The blowoff will then continue until the foam level subsides below theelectrode 35 and the switch T. D. S. opens. The engineer thus has avisual knowledge of the blow-oil but need not act because the blow-However, if the top light T. L. stays on for prolonged periods, theengineer may actuate the manually controlled blow-oil valve provided onthe locomotive for more rapid clearing of the steam Spa/ce.

In the embodiment shown in Figure 7 of the drawings parts substantiallyidentical with parts described in Figures l to inclusive have beenmarked with thesame reference numerals. In

Figure 7, however, a different electrode system is used. As thereinshown, a long electrode 50 projects from the top of the boiler shellinto the trough 25 near the rear end thereof to a level slightly abovethe bottom of the trough. A middle electrode 5I extends into the steamspace of the boiler but terminates slightly below the top of the troughat.

A short electrode 52 depends into the boiler and terminates at a levelabove the middle electrode 5I and above the trough.

As shown in Figure 8, the generator G energizes the main lines 40 and 4|as described above in connection with Figure 6. When the foam. level F.L. in the trough 20 contacts the electrode 50, current will flow throughrelay R1. The relay R1 will eiect a closing of the relay switch R. S.1but current cannot flow through this switch R. S.1 until a holdingswitch H. S. is closed. Therefore,

no discharge will be eiected. However, as the foam level-F. L. risesinto contact with the middle electrode 5l, current will ow through arelay Rz to close a relay switch R. S.: thereby causing current to ilowthrough the bottom light B. L. in the engineers cab to light the same.At the same time, however, current will also iiow through a contacter Cor actuator for the holding switch H. S. to close the switch H. S.Current will thus iiow through the solenoid valve S. V. to connect the'air pipes 42 and 43 and thereupon eiect an opening of the blow-ofi'valve for discharging the impurities out of the trough. When the foamlevel subsides away from the electrode 5I the relay switch R. S.: willopen but current will continue to ow through the contactar C therebymaintaining the holding switch H. S. in closed position and keeping thelight B. L. lit as well as keeping the solenoid switch open. Thiscurrent will ilow through the contactor C until foam subsides away fromthe electrode 50 whereupon the relay switch R. S4 will open therebybreaking the holding circuit and eiecting an opening of the hold,I ingswitch H. S. The solenoid valve and the bottom light will then shut oil.

When foam rises to a level above the middle electrode and contacts thetop electrode 52 a relay R3 is energized to close the normally openrelay switches R. $.31 and R. 5.32. Relay switch R. $.31, when closed,ilows current through the solenoid valve to open the same. Relay switchR. $.32, when closed, eiects a lighting of the top light T. L. in theengineers cab. When the foam level subsides awayfrom the electrode 52the relay R3 will be de-energized and the switches R. S31 and R. Se:will be opened to shut ol the top` light. However, the solenoid valve S.V. will not be closed because the same will be receiving current fromrelay R2. Even though relay R2 is then de-energized, the valve willremain open and the bottom light will remain lit until relay R1 isde-energized.

In the three-electrode system of Figure 7, therefore, the impurities inthe trough rst contact the long electrode 50 and, upon rising intocontact with the middle electrode 5| they effect the closing of acir-cuit to open the blow-off valve and to light the bottom light in theengineers cab showing that the blow-off valve is open. If foamdevelopment is quite rapid, and rises to a still higher level so as tocontact the top electrode 52, an additional light is lit in theengineers cab to show that bad foaming conditions exist in the boiler.If the top light remains lit for an appreciable time, the engineer mayopen a manually controlled blow-oil Ivalve for eiiecting a more rapidsubsiding of the foaming conditions.

The top electrode is also useful as a safety del a steam space, a

vice in the event that the middle electrode does not initiate theblow-ofi.I

Once the blow-oil' has been started by either or both the top and middleelectrodes I and 52, .the blow-01T will continue until the foamy watersubsides below the level of the long electrode 50.

Upon dropping away from the electrode 50 the circuits will all be brokenand the blow-ofi valve will close, but the level of impurities in thetrough will be near the bottom of the trough so that a clearsteamchannel is provided from the hot point of the boiler to the steamoutlets Il and I9. From the above descriptions of two embodiments ofthis invention it should `be understood that an open topped collectingbox or trough is mounted-in a steam boiler to extend under the steamoutlet and longitudinally of the main flow of boiler water in the-boileras indicated by the arrows in Figure 2 of the drawings. The troughmaintains an elongated clear steam channel from the hottest portion ofthe boiler to the steam outlet. Foam, light water or otherimpuritieswhich rise to levels in the boiler tending to choke olf thesteam space must spill into the trough at some point along its length.Upon spilling into' th trough the foam is collapsed and the impuritiesare collected in the trough for discharge out of the boiler' wheneverfoamy water' tends to choke oif the steamspace.

It will, of course, be understood that various details of constructionmay be varied through a wide range without departing from the principlesof this invention and it is, therefore, not the pura prow-like nose atone end thereof, an opening through the opposite end thereof adapted tore-v ceive av steam pipe therethrough, a side wall of said box having acut-away portion, and a door for closing said -cut-away portion of theside wall.

4. In a locomotive boiler having a water space, a steam space, a steamoutlet and a fire box in spaced Vlongitudinal relation from the steamoutlet, the improvement oi'an elongated open topped collapsing boxmounted in the boiler to extend longitudinally from a point adjacent there box under the steam outlet to a point forward of the steam outlet,said box having side and end walls projecting into the' steam space butterminating at a level about' thirteen to twenty inches above the top ofthe lire box, and said side and end walls being spaced from the walls ofthe boiler to provide communication between the box and steam spacealong the entire length of the box. 5. In a locomotive boiler having awater space,

spaced relation from the boiler walls along the entire length of thebox, said box extending under the steam outlet to a point adjacent thefire box, said open topped box having side and end walls projectingintov the steam space but ter- I minating beneath the steam outlet,electrodes pose to limit the patent -granted hereon otherwise thannecessitated by the scope of the appended claims.

We claim "s our invention:

1. In a steam boiler including a water space. steam outlet"communicating with the steam space, and a hre box in longitudinallyspaced relation from the steam outlet.

the improvements of an elongated open topped trough mounted in theboiler to extend beneath the steam outlet and in a longitudinaldirection .therefrom toward the fire box, said trough being incommunication with the steam space along its entire length and havingsides and end walls spacedfrom the boiler walls and projecting into thesteam space-above the normal water level in the boiler for providing aninlet to the trough at a level below the steam outlet and above thenormal water level to'intercept into the trough .foam and light waterdirect from the boiler water boiler walls and having side and end wallsprojecting into the steam space above the normal water level butterminating below the steam outlet, said trough extending from a pointadjacent the hottest portion'of theboiler under the steam outlet tomaintain a clear steam channel to the outlet communicating along itslength with the projecting into the steam space of the boiler adapted tocontact foam and light water when th'e' same rises to a level above thetop of the box, 'and means controlled by` said electrodes fordischarging impurities out of the box whenever the foam level reachesthe levels of the electrodes. 1

6. In a locomotive boiler having a water space, a steam space, a steamdome above the steam space and a main throttle pipe extending throughthe steam spaceand having an inlet end projecting upwardly into thesteam dome, the improvement of an elongated open topped foam collapsingtrough extending under the steam dome and receiving the throttle pipeinto one end thereof, said box being spaced from the boiler walls alongits entire length, a drain outlet for said foam coll lapsing trough, ablowoi valve in said drain outlet, and electrode means suspended intheboiler to contact 'foam and light water when the same develops tolevels above the -top of the trough for opening the blow-oil.' valve toremove impurities out of theA trough.

7. An 'automatic foam-collapsing and blow-oil' system for boilers whichcomprises an elongated open topped foam-collapsing box mounted in theboiler to extend under the steam outlet in the direction ofv major waterilow in the boiler, said box being spaced from the vboiler walls alongits entire length, a blow-off valve forsaid boiler, a drain line joiningthe lower portion of the open topped box with said blow-oir valve, adrain outlet joining the bottom portion of the box with the steam space,and means for discharging materials collected in the trough out of theboiler.

3. 1A foam collapsing trough for steam boilers comprising an open toppedelongated box having -interior of the boiler, and electrode meansadapted to be contacted by water at levels above the top of the box foractuating the blow-off valve to discharge materials out of the box.

8.In anautomatlc blow-off system for steam boilers including alightwater and foam-collapsins trough-mounted in the upper portion of theboiler in spaced relation from the boiler walls throughout the entirelength of the trough to receive impurities directly from the boilerwater at a level'above the normal water level but below thesteam outletof the boiler, the improvements ,lay circuit actuated by the other ofsaid electrodes connected to the solenoid valve for immediately openingthe same to open the blow-oil valve whe'reby the first mentionedelectrode will elect discharge of impurities out of the trough onlyafter the foam and light water remain in contact therewith for apredetermined time While the second electrode will effect immediateopening of the discharge valve upon contacting the foam and light water.

9. An automatic impurity-collecting and discharge system for steamboilers which comprises an open-topped collecting box mounted in theboiler to extend under the steam outlet and arranged to receive foam andlight water direct from the boiler water along the entire length of thebox at a level above the normal water level in the boiler but below thesteam outlet, an electrode projecting into the collecting box to alevelnear the bottom thereof, 'a second electrode projecting into the steamspace of the boiler near the top ofthe collecting box, a solenoid airvalve, an air operated' blow-oir valve controlled by the solenoid valve,a drain outlet for the collecting box connected to the blow-off valve,an electrical circuit closed by foam and light water contact with bothof said electrodes to actuate the solenoid valve for opening theblow-oil valve, and holding means in said electrical circuit to maintainthe solenoid valve in open position for continuing the blow-oil untilthe foam and light water level asesinas subsides below the longerelectrode projecting in-1I to the box.

10. The method of preventing water and impurity carry over into steamoutlets of operating steam boilers which comprises forming a nonsteamgenerating localized elongated course beneath the steam outlet of theboiler and extend ing toward the hottest portion of the boiler,collecting impurities directly from the boiler along the entire lengthof said course at a level below the steam outlet but above the normalwater level. and discharging the collected impurities to main tain anon-steam generating clear steam channel along the length of the courseto the steam outlet.

1l. The method of operating steam boilers to produce high quality steamwhich comprises collecting impurities from the boiler water along all ofan elongated path extending from the hottest .portion of the boiler toand under th steam outlet at a level beneath the'steam outlet but abovethe .normal water level, and discharging the collected impurities out ofthe boiler whenever the foam and light water level in the boiler risesabove 4a predetermined level.

, light water directly"` from the boiler -water along .the entire lengthof the course at-a level about thirteen to twenty inches above the topof the fire box, and blowing the collected impurities out of thelocalized course whenever foam and light water are developed to apredetermined level in the boiler.

LEWIS O. GUNDERSON. OLAND W. CARRICK.

